Recently, with developments on digitalization of electric devices and downsized and higher-speed electronic devices such as personal computers, capacitors, downsized but having large capacitance and low impedance in a high-frequency region, are demanded, and there have been proposed solid electrolytic capacitors using electroconductive polymer having electron conductivity as solid electrolyte. Particularly, since products having a larger capacitance are demanded, laminated solid electrolytic capacitors have been produced which are obtained by laminating a plurality of capacitor chips and encapsulating them.
For example, JP-A-2002-319522 (Patent Document 1; EP 1 160 809) discloses a solid electrolytic capacitor which reduces the size and increases the capacitance by downsizing the space required for electric integration of the anode body, and further enables to attain reliable electrical connection between the anode bodies with low resistance.
FIG. 1 is a cross-sectional view showing a structure of a conventional laminated solid electrolytic capacitor.
Generally, a solid electrolytic capacitor element (6) is produced by forming an oxide film layer of a dielectric body (2) on a surface of an anode substrate (1) consisting of a metal foil or a thin sheet having a large specific surface area increased by etching treatment and, generally, after further providing a masking layer (5) thereto, forming sequentially thereon a solid semiconductor layer (3) (hereinafter referred to as solid electrolyte) serving as a cathode part and a conductor layer (4) of electroconductive paste or the like. By laminating a plurality of thus-produced capacitor elements (6) unidirectionally, providing a conductor layer (4) as appropriate, further adding electrode lead parts (6, 7) and by encapsulating the whole by resin (9), a laminated solid electrolytic capacitor is produced.
In a laminated solid electrolytic capacitor, the capacitance of the capacitor can be increased by increasing the thickness and the number of the capacitor elements (6) to be laminated. However, when the total thickness of the laminated elements increases, the capacitor elements become readily exposed from the encapsulating resin or defects in appearance such as a pinhole or a weld line in the resin encapsulating the capacitor chip are likely to occur. Therefore there has been a problem of the limitation on the total thickness of the laminated capacitor elements.    Patent Document 1: JP-A-2002-319522